The value of spinal computed tomography in diagnosis of herniated lumbar discs

Summary In this study the diagnostic value and topographical accuracy of spinal computed tomography (CT) in the preoperative diagnosis of lumbar disc herniations were tested in 36 patients with surgically proven herniated discs. All patients also underwent metrizamide myelography. CT findings and myelograms were compared and correlated with the surgical observations. Especially in demonstrating exact diagnosis (lateral or more medial protrusion), and in showing the extent of upward or downward displacement of free disc material, CT provides valuable preoperative information. As a non-invasive diagnostic procedure, spinal CT scan may replace lumbar myelography in many patients with radicular lumbar pain.     

A comparison of CT scanning and myelography in the diagnosis of lumbar disc herniation

Computerized tomographic (CT) scanning of the fourth and fifth lumbar disc spaces with the GE CT/T8800 scanner followed by metrizamide myelography was obtained for 134 consecutive patients with suspected lumbar disc disease. There was an overall concordance rate of 85% between CT scanning and myelography. In those 52 patients treated by surgery, concordance between the CT and the myelogram was similar at 86.5%. Myelography and surgical findings were in agreement in 94.2% of cases, while CT findings and surgical finding agreed in 92.3% of cases. The authors' data indicate that the CT scan is as accurate as myelography in the diagnosis of lumbar disc disease. When the CT scan interpretation is supported by clinical findings, the myelogram may be eliminated in the preoperative patient. Myelography may be reserved for equivocal cases.     

A comparison of computed tomography and myelography in the diagnosis of lumbar disc herniation

Summary Ninety patients suspected to have a herniated lumbar disc were examined by myelography and computed tomography (CT). Of these, 37 were subjected to surgery. The surgical findings were in agreement in 21 patients (57%) with the myelograms and in 28 patients (76%) with the CT examinations. False-positive CT examinations were found in only one patient. CT is as reliable as myelography in the primary diagnosis of disc herniation.     

A comparison of computed tomography and myelography in the diagnosis of lumbar disc herniation

Ninety patients suspected to have a herniated lumbar disc were examined by myelography and computed tomography (CT). Of these, 37 were subjected to surgery. The surgical findings were in agreement in 21 patients (57%) with the myelograms and in 28 patients (76%) with the CT examinations. False-positive CT examinations were found in only one patient. CT is as reliable as myelography in the primary diagnosis of disc herniation.     

CT硬膜外造影对腰椎管狭窄症的诊断价值

目的：探讨硬膜外造影后CT(CT-E)对腰椎管狭窄症的诊断价值及影像特征。方法：对27例腰椎管狭窄症患者行腰椎X线平片及单纯CT检查后再行CT-E检查。CT—E扫描椎体下1／3、椎间隙、椎体上缘平面，结合单纯CT及手术所见行对比分析。结果：CT-E诊断中央管狭窄3例，中央管伴侧隐窝狭窄2例，侧隐窝狭窄16例，神经根管狭窄4例，椎问孔狭窄2例。与于术所见吻合25例，诊断准确率达93％；单纯CT与手术所见吻合23例．诊断准确率为85％。结论：CT—E对腰椎管狭窄症更具有定性、定位诊断作用，可为有限化手术提供依据。     

Role of computed tomography and myelography in the diagnosis of central spinal stenosis

In order to evaluate radiographic methods for diagnosing central lumbar stenosis, we reviewed the computed tomography scans and myelograms of twenty-four patients who underwent surgical decompression for central lumbar stenosis. In the diagnosis of central lumbar stenosis, the measurement of the anterior-posterior diameter of the osseous canal by computed tomography was less reliable than the measurement of the dural sac by myelography. The dimensions of the canal derived from computed tomography provided a correct diagnosis in 20 per cent of the patients, while myelography was accurate 83 per cent of the time. The effectiveness of computed tomography was improved when the cross-sectional area of the dural sac was measured. We suggest that a narrow dural sac, demonstrated by myelography or by computed tomography, reliably indicates central spinal stenosis.     

The use of computerized tomography in evaluating non-visualized vertebral levels caudad to a complete block on a lumbar myelogram. A review of thirty-two cases

In thirty-two patients who demonstrated a complete or almost complete block on a lumbar myelogram, computerized tomography of the non-visualized vertebral levels caudad to the block was performed prior to surgical intervention. The purpose of this study was to evaluate the clinical value of computerized tomography in detecting a lesion that is caudad to the level of a myelographic block. For twenty-three patients the cause of the myelographic block was stenosis of the spine; for five patients, a combination of stenosis of the spine and herniation of a disc; for one patient, herniation of a disc between the fourth and fifth lumbar vertebrae alone; for two patients, arachnoiditis; and for one patient, kyphosis secondary to fracture. A total of fifty vertebral levels that could not be visualized because of the block were evaluated. Thirty (60 per cent) of the non-visualized vertebral levels, in nineteen (59 per cent) of the thirty-two patients, demonstrated stenosis of the spine or a herniated disc that was confirmed at the time of surgical treatment. The value of computerized tomography for the evaluation of the vertebral levels caudad to the level of a complete or almost complete block on a lumbar myelogram was threefold. First, it provided visualization of the vertebral levels that could not be evaluated by the myelography. Second, the findings on computerized tomography provided information that was essential for preoperative planning and it removed the so-called exploratory element from the operative procedure.(ABSTRACT TRUNCATED AT 250 WORDS)     

The neuroradiographic diagnosis of lumbar herniated nucleus pulposus: II. A comparison of computed tomography (CT), myelography, CT-myelography, and magnetic resonance imaging

The accuracy of computed tomography (CT), myelography, CT-myelography (myelo-CT) and magnetic resonance imaging (MRI) for the diagnosis of lumbar herniated nucleus pulposus (HNP) is compared prospectively in 59 patients, all of whom underwent surgical exploration. All tests were read independently of each other and the level of confidence in each diagnosis was recorded. The results are based on the negative (61) as well as positive (59) findings at the 120 disc sites (level and side) explored. Magnetic resonance imaging was the most accurate test (76.5%) compared with myelo-CT (76.0%), CT (73.6%), and myelography (71.4%). The false positive rate was lowest for MRI (13.5%) followed by myelography (13.7%), CT (13.8%), and myelo-CT (21.1%). The false negative rate was lowest for myelo-CT (27.2%) followed by MRI (35.7%), CT (40.2%), and myelography (44.1%). In that subset of 19 patients who had prior surgery, myelography was the most accurate means of diagnosing lumbar HNP (88.8%), followed by MRI (83.3%), myelo-CT (78.4%), and CT (72.6%). The false positive rates in these patients were 11.6% for myelography, 13.2% for MRI, 14.5% for CT, and 16.4% for myelo-CT; the false negative rates were 22.7% for MRI, 24.4% for myelography, 29.5% for myelo-CT, and 47.7% for CT. Magnetic resonance imaging compares very favorably with other currently available imaging modalities for diagnosing lumbar HNP. Magnetic resonance imaging is painless, has no known side effects or morbidity, no radiation exposure, and is noninvasive. The authors recommend it as the procedure of choice for the diagnosis of most lumbar disc herniations.     

Metrizamide-enhanced computed tomography as an adjunct to metrizamide myelography in the evaluation of lumbar disc herniation and spondylosis

Eighty patients with operatively proven lumbar disc herniation or lumbar spondylosis were preoperatively evaluated with metrizamide myelography followed by metrizamide-enhanced computed tomography (CT). The x-ray films were reviewed without knowledge of the operative findings, and the patients were subdivided into those with disc extrusions, spondylosis, or recurrent abnormalities. For the group as a whole, CT was correct in 82% and myelography was correct in 77%. Both CT and myelography together were accurate in 91%, a significant improvement (P less than 0.02). The authors conclude that, if both studies are performed, the percentage of cases correctly diagnosed is increased. Therefore, both metrizamide myelography and metrizamide-enhanced CT should be obtained in selected cases. A review of the literature is included.     

Foraminal and extraforaminal lumbar disc herniation: diagnosis and treatment

During a 1-year period from December 1, 1984, through November 30, 1985, a total of 174 patients underwent lumbar discectomy for herniated nucleus pulposus. Eighteen (10.3%) were diagnosed as having foraminal or extraforaminal disc herniations. Sixteen patients are included in this study. All patients were evaluated with computed tomography, metrizamide myelography, discography, and discography-enhanced computed tomography (disco-CT). Accurate diagnosis of foraminal or extraforaminal herniation was made with disco-CT in 15 of 16 cases (93.8%), compared with discography alone (37.5%), computed tomography alone, and/or myelography-enhanced computed tomography (50%) and myelography alone (12.5%). Surgical treatment with bilateral hemilaminectomy, partial medial facetectomy, and partial internal foraminotomy, if needed, followed by discectomy is very effective and the favored surgical management for nerve root decompression in most all cases.     

The neuroradiographic diagnosis of lumbar herniated nucleus pulposus: I. A comparison of computed tomography (CT), myelography, CT-myelography, discography, and CT-discography

The accuracy of five imaging modalities for the diagnosis of lumbar herniated nucleus pulposus (HNP) is compared prospectively in 124 patients, all of whom underwent surgical exploration. All tests were read independently of each other and the level of confidence in each diagnosis was recorded. The results are based on negative (106) as well as positive (125) findings at the 231 disc sites (level and side) explored. Computed tomography-discography (disco-CT) was the most accurate test (87%) compared to 77% for CT-myelography (myelo-CT), 74% for CT, 70% for myelography, 64% for disc injection pain, and 58% for discography. The false positive rate was lower for disco-CT (19%) than for myelo-CT (24%), CT (24%), and myelography (30%). The false negative rate was also lower for disco-CT (8%) than for myelo-CT (22%), CT (29%), and myelography (30%). Disco-CT was the most accurate test (94%) in patients who had prior disc surgery compared with 81% for myelo-CT, 80% for CT, and 74% for myelography. Disco-CT was also the most accurate test for patients with foraminal HNP (91% compared with 71% for CT, 65% for myelo-CT, and 58% for myelography). Disc injection reproduced the patient's clinical pain pattern in only 36% of herniated discs. This test has high specificity (89%), but low sensitivity (43%). The risks from myelography followed by discography within a 72-hour period are similar to those reported for myelography alone. Disco-CT is the most accurate of these tests (P less than 0.05) for the diagnosis of lumbar HNP.(ABSTRACT TRUNCATED AT 250 WORDS)     

Computed tomography in the diagnosis of a herniated disk at the L5-S1 level

Six patients with a normal myelogram were found to have evidence of a herniated nucleus pulposus (HNP) at the L5-S1 level on computed tomography (CT) scan. In all six patients, the presence of the herniated disk was confirmed at surgery. Five of the six herniations were lateral. The authors found no patients with an abnormal myelogram and a normal CT at the L5-S1 level in a technically good study. The sensitivity of the CT in diagnosing an HNP at the L5-S1 interspace is greater than with myelography if images in the exact plane of the disk can be obtained.     

Diagnosis of nerve root compression. Myelography, computed tomography, and MRI.

Current technology and published studies support the preferential use of MRI in the diagnosis of cervical myelopathy. In cervical radiculopathy, data support the use of either contrast-enhanced CT or MRI. We prefer MRI as the initial diagnostic test because of the obvious advantage of its noninvasive nature. Similar to myelography, MRI permits visualization of the entire cervical canal and spinal cord. Unlike routine CT, MRI visualizes the spinal cord and nerve roots in two planes and is better in detecting unsuspected pathology at other cervical segmental levels. Because the quality of MRI scans in the cervical spine is subject to more variation than in the lumbar spine, anticipated pathology is sometimes not clearly visualized by cervical MRI. Under such circumstances, we obtain a water-soluble myelogram followed by contrast-enhanced CT. Because inaccurate radiographic diagnosis is one of the identifiable causes of poor outcome in surgical therapy for cervical spondylosis, accurate visualization of pathology in terms of its location, nature, and extent is imperative before performing decompressive cervical spine surgery.     

Computed tomography scanning after chymopapain injection for herniated nucleus pulposus. A prospective study

Fifty consecutive patients treated with chymopapain injection for a clinical and radiographic diagnosis of herniated nucleus pulposus were evaluated prospectively. All patients had a prechymopapain computed tomography (CT) scan and a three-month postinjection CT scan. In addition, ten patients (20%) had a six-month postinjection CT scan. All scans were interpreted blindly. Only six patients (12%) had obvious changes in the size of the disc when preinjection and three-month postinjection CT scans were compared. By six months, however, seven of ten patients (70%) had obvious changes in their CT scan. Seven patients (14%) were considered chymopapain treatment failures and were later treated with surgical discectomy. Only two of these seven patients (30%) had obvious changes in their three-month CT scan. Chymopapain injection did not alter the size of the herniated portion of the disc during the first three months after chymopapain injection. A decision to operate for presumed chymopapain failure should therefore be based on clinical grounds, rather than on the three-month CT appearance of the herniated disc.     

Lumbar intervertebral disc cyst as a cause of radiculopathy.

BACKGROUND CONTEXT: Lumbar radiculopathy is commonly caused by degenerative conditions such as a herniated disc or lumbar spinal stenosis. Less common etiologies include intraspinal extradural masses such as synovial cysts and gas-containing ganglion cysts. Intraspinal extradural cysts that communicate with the intervertebral disc are a rare entity and thus, an uncommon cause of lumbar radiculopathy. There are only ten cases of an intervertebral disc cyst reported in the literature. PURPOSE: To document the first reported case of an intervertebral disc cyst in North America. Two series of Japanese patients with intervertebral disc cyst confirmed radiographically and intraoperatively have recently been reported. STUDY DESIGN: A case report of an intervertebral disc cyst at L4-5 causing an L5 radiculopathy. OUTCOME MEASURES: Japanese Orthopaedic Association score for low back pain. METHODS: The patient and the authors involved in the patient's management were interviewed. All medical records, radiographic imaging studies, intraoperative findings, and pertinent literature were also reviewed. RESULTS: Preoperative magnetic resonance imaging (MRI) scan demonstrated a well-localized cyst compressing the ventral aspect of the thecal sac at L4-L5. Discography and subsequent computed tomographic (CT) scanning demonstrated the cyst communicating with an intervertebral disc herniation via an annular rupture. Decompressive discectomy and surgical excision of the disc cyst from the spinal canal resulted in complete recovery and resolution of the preoperative radiculopathy. Clinical improvement was documented using the JOA scoring system. Patient's preoperative score was 4/15, and postoperative score was 15/15. CONCLUSION: Although exceedingly rare, an intervertebral disc cyst should remain in the differential diagnosis of any extradural intraspinal mass ventral to the thecal sac. Diagnosis of an intervertebral disc cyst requires recognition of this uncommon entity and a high index of suspicion. Discography and post-discography computerized tomography (CT) scan confirm the diagnosis. Operative treatment includes decompression, and excision of the cyst and is reserved only for cases in which the cyst results in clinical symptoms unresponsive to nonoperative management.     

Diagnostic value of computed tomography in recurrent pain after discectomy

Intravenously enhanced computed tomography (CT) was used in patients in whom the differential diagnosis between recurrent herniated disc and postoperative scar was considered. Enhanced CT images demonstrated postoperative herniated discs more accurately than clinical criteria, myelography, or plain or postmetrizamide CT. The scar tissue shows contrast enhancement, but recurrent disc herniation does not. Therefore, contrast-enhanced CT is considered to be a valuable aid in distinguishing between recurrent disc herniation and hypertropic scar formation.     

Intradural disc herniations in the cervical, thoracic, and lumbar spine: report of three cases and review of the literature

The clinical, neuroradiological, and surgical management of three cases of intradural disc herniations--one each in the cervical, thoracic, and lumbar regions--are presented. Intradural disc herniations comprise only 0.27% of all herniated discs. Three percent occur in the cervical, 5% in the thoracic, and 92% in the lumbar spinal canal. Those with cervical or thoracic lesions frequently exhibit profound myelopathy, whereas those with lumbar lesions demonstrate radicular or cauda equina syndromes. Although varying combinations of the MRI, non-contrast CT, myelogram, and myelo-CT scans may at times fail to accurately establish the diagnosis of an intradural disc herniation prior to surgery, the index of suspicion raised by the lack of clinical correlation with surgical findings justifies an intradural exploration.     

Computed tomographic metrizamide myelography in Chiari malformation in adult--special reference to the diagnostic values of reconstruction CT

Three adult patients with a clinical diagnosis of Chiari malformation were examined by computed tomography after intrathecal injection of metrizamide via the lumbar route. In all patients Chiari malformation was demonstrated as a soft tissue oval mass at the level of C1-C2 vertebral body that was intradural and posterior to the medulla and the upper cervical spinal cord. These findings were more accurately visualized in saggital and in frontal reconstructed CTs. In one patient the spinal cord was measurably enlarged at the upper thoracic level. A delayed scan was obtained in another case at 24 hours after the injection and the syrinx was remained opacified whereas the density of cerebrospinal fluid and parenchyma decreased. In the third patient no abnormality of the cord was demonstrated either in CT or myelography. High resolution CT, especially reconstruction-CT appears to be more reliable than myelography and should be the examination of choice in the diagnosis of Chiari malformation.     

腰椎间盘突出CT扫描三维定位诊断

目的：研究椎间盘突出的三维定位,为腰椎间盘突出患者提供更精确的诊断依据。方法：对40例椎间盘突出CT扫描后进行多平面重建,得到矢状位图像。用1－4四个数字代表突出髓核在横断位上的位置,在横断位或矢状位上测量髓核后突的程度,在矢状位上测量髓核上下移位的长度。按照左右、前后、上下的顺序来描述髓核突出的部位、后突程度和长度,并与手术结果对照。结果：三维定位提供的部位、程度和长度与手术结果相符。结论：多平面重建图像和三维定位方法是可靠的,可为椎间盘突出的诊断提供更精确可靠的依据。     

Reoperation after treatment of a disk hernia. Comparison between radiology and surgical findings in 18 cases

Eighteen patients with recurrent sciatica after lumbar disc surgery were investigated by both, myelography and computed tomography (CT) before reoperation. The radiological diagnosis according to the original x-ray report was correlated with the surgical findings at reoperation. Myelography reports describe morphological changes but often contain no definite diagnosis. CT reports usually contain detailed tissue diagnosis, but correlation with surgical findings is generally poor. Review of the original x-ray films leads to the following conclusions: At present, myelography is always indicated, except in suspected extreme lateral disc herniation. CT should be reserved for particular clinical or myelographic problems.